45 For now, alas, not secretly nor under cover, but openly, with all sense of shame put aside, now by word again by writings, by theatrical productions of every kind, by romantic fiction, by amorous and frivolous novels, by cinematographs portraying in vivid scene, in addresses broadcast by radio telephony, in short by all the inventions of modern science, the sanctity of marriage is trampled upon and derided; divorce, adultery, all the basest vices either are extolled or at least are depicted in such colors as to appear to be free of all reproach and infamy. Books are not lacking which dare to pronounce themselves as scientific but which in truth are merely coated with a veneer of science in order that they may the more easily insinuate their ideas. The doctrines defended in these are offered for sale as the productions of modern genius, of that genius namely, which, anxious only for truth, is considered to have emancipated itself from all those old-fashioned and immature opinions of the ancients; and to the number of these antiquated opinions they relegate the traditional doctrine of Christian marriage.
Source: Casti Connubii (Vatican.va)